\begin{tabular}{l*{11}{c}}
\hline
                 &\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}&\multicolumn{1}{c}{Yr}\\         &\multicolumn{1}{c}{4}&\multicolumn{1}{c}{5}&\multicolumn{1}{c}{6}&\multicolumn{1}{c}{7}&\multicolumn{1}{c}{8}&\multicolumn{1}{c}{9}&\multicolumn{1}{c}{10}&\multicolumn{1}{c}{11}&\multicolumn{1}{c}{12}&\multicolumn{1}{c}{13}&\multicolumn{1}{c}{14}\\ \hline  \emph{Second stage}\\
Enrollment  &       4.951***&       2.997** &       1.502   &       1.835   &       2.883   &       3.253   &       4.897** &       4.563** &       4.750** &       5.889** &       6.122** \\
            &     (1.203)   &     (1.361)   &     (1.428)   &     (1.765)   &     (1.863)   &     (2.034)   &     (2.155)   &     (2.298)   &     (2.280)   &     (2.382)   &     (2.424)   \\
\hline
Controls    &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   &         Yes   \\
F-stat      &         227   &         236   &         240   &         236   &         235   &         237   &         229   &         227   &         230   &         238   &         240   \\
N           &        3667   &        3663   &        3647   &        3627   &        3600   &        3578   &        3546   &        3522   &        3477   &        3429   &        3396   \\
Mean of Y   &       11.81   &       14.82   &       15.74   &       16.34   &       17.11   &       18.28   &       19.13   &       19.95   &       21.10   &       22.41   &       23.43   \\
\hline
\end{tabular}
